Howdy all
On my new RR, I have a couple of locations that just beg for a tunnel. On my last RR, I built the tunnel box out of PT 2x stock. Ive heard others using chimney flue, and, yet others using cinder block walls and patio block floors and roofs.
What’s your preference for building a tunnel? Mine are going to be about 5’ long or so, nothing earth shattering, but long enough.
-=Bob